System for transporting sheet material



Sept. 26, 1967 G. A. DEAN 3,343,690

SYSTEM FOR TRANSPORTING SHEET MATERIAL Filed Feb. 14, 1966 5She9ts-$heet 1 Sept. 26, 1967 s. A. DEAN 3,343,590

SYSTEM FOR TRANSPORTING SHEET MATERIAL Filed Feb. 14, 1966 5Sheets-Sheet 2'6 Z6 Z7 ,6 5/4/03 7 2/ ,7 5 7 i I :"EFf-li-ZFEEEEi-E 5 II I I l J 35 1 1,1 l/VVf/V r04 25 35 650m; A. 0544/ Sept. 26, 1967 G. A.DEAN 3,343,690

SYSTEM FOR TRANSPORTING SHEET MATERIAL Filed Feb. 14, 1966 5Sheets-Sheet 5 A rromvs y:

United States Patent 3,343,690 SYSTEM FOR TRAN SPGRTING SHEET MATERIALGeorge A. Dean, Overland Park, Kans., assignor to Dean ResearchCorporation, Kansas City, Mo., a corporation of Missouri Filed Feb. 14,1966, Ser. No. 527,175 13 Claims. (Cl. 2146) The present invention isdirected to a system for transporting articles, and more particularly tothe accumulation and shifting of sheet material such as glass, paper,wood, cardboard, and others.

It is among the objects of the invention to provide a system which issimple in construction, efiicient in operation, is capable of rapidmanipulation to stack and transport sheets, and which is adaptable foruse with sheets of various sizes and for sheets of more than one size ina single stack.

In practicing the invention there is provided a head having a top andone or two sides. The head is hollow and is connected to a source ofvacuum. The interior of the head has perforations and is adapted to holda stack of sheets by the vacuum which supports the stack. Because thehead is open at the bottom, sheets may be added thereto from below.Since the head is open on at least two sides, the sheets may be nestedagainst closed sides regardless of the dimensions thereof and theapplied vacuum will hold all of the sheets.

Various other elements are provided to complete the structure. In thehead is a leveling plate contacting the top sheet and operated up ordown by suitable means, such as a pneumatic ram to pick up and hold astack of sheets. A support for the head is pivoted so that the stack maybe transferred to a holding area or tractor or rack by tilting the headand releasing the vacuum. The assembly is usually mounted on an overheadtrack so that it may be moved to desired areas for operation.

In the accompanying drawings constituting a part hereof, in which likereference characters represent like parts, there are shown twoembodiments of the invention. In said drawings:

FIG. 1 is a side elevational view of one embodiment of the inventionshowing the operation of adding a sheet to a stack already held in thehead;

FIG. 1A is a side elevational view of a rack, buck or holder for a stackof sheets, illustrating the transfer thereof from the head;

FIG. 2 is a perspective view looking up from underneath the head of FIG.1, showing the arrangement for holding the sheets;

FIG. 3 is an enlarged fragmentary cross-sectional view of one corner ofthe head illustrating the manner in which the vacuum holds the stack ofsheets within the head;

FIG. 4 is a top plan view taken along line 44 of FIG. 1 showing theconstruction of the endless conveyor belt;

FIG. 5 is a side elevational view of the belt of FIG. 4 with means forlifting a sheet into the stack;

FIG. 6 is a modified form of the invention in which the stack of sheetsis vertically placed; and

FIG. 7 is a view similar to FIG. 1A in which the rack or buck is formedto hold the stack shown in FIG. 6.

Referring to the drawings, on an overhead support 1 there is fixed apair of spaced rails 2 and 3. A trolley 4 is held for movement on therails by wheels 5 and 6. Hanger 7 depends from trolley 4 and has a pivot8 to which is linked support 9. Means are provided for moving support 9or holding it in adjusted position, such means being manual, mechanical,hydraulic or any other known means.

The head includes a top 10 and sides 11 and 12 at right angles to eachother and to top 10. The bottom and the other two sides of the box-likehead are open. Sides 11 and 12 are hollow having a cavity 13 thereinadapted to be connected to a source of vacuum by duct 14. Within thehead is leveling plate 15 which is fitted with actuator 16 which may bea hydraulic ram serving to raise and lower the stack of sheets. Ceiling17 of plate 15 is perforated and covers hollow space 18 therein. Sides19 and 20 of the head are also perforated so that channels ofcommunication may be established with cavity 13 of the head. The bottomof the head structure is open to permit entry of the sheets.

Means are provided to mask or cover portions 21 and 22 which are abovethe top of leveling plate 15 in its several adjusted positions. Suchmeans may be, for example, roller curtains mounted on plate 15 with thefree ends fixed at the junction of head top 10 and the sides 11 and 12of the head. Seals 23 are provided in the sides of the head andcooperating level plate to prevent loss of vacuum. Such seals areusually of rubber or other elastic materials.

Referring to FIG. 1, an endless conveyor 25 for bringing sheets 26, sayof glass, is located below the head and its associated elements, theconveyor passing around roller 27. Assuming that there is already astack of sheets 28 being held by the vacuum in the head, and it isdesired to add another sheet, the conveyor is stopped with sheet 26directly below the stack. Actuator 16 is operated to lower the stackuntil it touches sheet 26 as best shown in FIG. 3. Said sheet takesposition 26" making contact with seal 23. The suction of the vacuum incavity 13 draws out the air from the edges 29 of the sheets and frombetween the stack and the sheet, thus holding it as part of the stack.By reason of covers 21 and 22 there is no loss of vacuum above theleveling plate.

In one method of operation of the invention and referring to FIG. 1, thehead would move downward somewhat vertically such that the stack 28would embrace sheet 26. Upon contact, actuator 16 would move theleveling plate 15 vertically to allow sheet 26 to assume the position of26". In other words, the leveling plate must move upward to allow thenew sheet 26' to be accumulated.

When the head has accumulated the correct number of sheets, the entireassembly moves along the track 2 and 3 until it clears the conveyor fromwhich the material was accumulated. The head is then rotated as shown inFIG. 1A in the direction of arrow 32 and released onto the rack.

To discharge the stack, it is moved to a position adjacent to a rack asshown in FIG. 1A. The rack has a base 30 and a sloping side 31. Theangle of slope is about 7. Support 9 is swung in the direction of arrow32 until it is locate-d just above the rack, the vacuum is released andthe stack falls onto the rack at the angle shown, without any danger ofbreakage of glass.

The cavity within the leveling plate is used to obtain the pressuredifferential across the stack from top to bottom necessary to lift thematerial. The cavity within the sides is used to act as a pump toexhaust the air film between sheets, such that the plates then become asomewhat homogenous mass. If the material being accumulated is glass inrather large sheets, it may be practical to score the sheets or plates,as shown at 33, to the smaller size just prior to accumulation. Theselarge plates may then be accumulated and transported to a storage areaand just prior to release, it the leveling plate is caused to deflect atthe scoring points, the stacked large plates would break along thescored lines to produce the smaller plates.

In FIG. 5 is shown a mechanism for lifting a sheet into the levelingplate. It is particularly adapted for use where heavy loads are to betransported, such as ton lots of sheets, it is desirable to hold thehead substantially stationary and lift the sheet up to the head. Theendless conveyor belt has a pair of outside belts 35 (FIG. 4) andcentral spaced belts 36 and 37. A table 38 is mounted on ram 39. It hasa series of spaced parallel longitudinal ribs 43 adapted to be liftedinto spaces 40, 41 and 42 between the belts, by the action of ram 39.Such movement raises sheet 44 into contact with stack 28.

Glass 43 on the conveyor may be elevated to the accu- V mulated stack bya vertically actuated table mounted within the conveyor. This conveyortable is timed by controls to the leveling plate. The table orpositioner 38 moves vertically, lifting the glass plate until it makescontact with the accumulated stack 28 and on contact, the leveling platemoves upward until the upper surfaces of plate 43 move into the pumpingaction of the cavity, once again locking it to the plate immediatelyabove, and the cycle is now ready for the next plate moving along theconveyor.

The conveyor table or positioner 38 is equipped with positioning fingersand rolls to assure alignment of the plate just prior to its verticalmotion to the accumulated stack. When the head assembly has accumulatedthe desired stack, it then moves horizontally by the tractor away fromthe conveyor to a depot or holding area.

The head assembly, having traveled away from the conveyor to the rackarea, is simply rotated by hydraulics or other standard methods to theposition shown on the rack. The cavity pressure is returned toatmospheric and the head then swings clear, leaving the stacked glass onthe rack. The head assembly then returns to its position over theconveyor for further accumulation.

In FIG. 6 is shown a modified embodiment which is at present preferred,especially where heavy weights of sheets are to be transported. Conveyor35, shown in FIG. 5, carried sheet 104 which is moved vertically upwardtowards the head. The vacuum pulled through opening 103 maintains avacuum in cavity 13 through perforated wall 19, much in the same manneras FIG. 3. However, in place of the rubber seal, there is a secondcavity in the form of a slit 101 running in the same manner as the sealdid. A vacuum is pulled through duct 102 causing high flow of air topass through the slit 101. The vacuum pressure in duct 102 is relativelylow at this time. When sheet 104 is moved into the relative vicinity ofslit 101 a negative pressure is created between sheet 104 and the sheetimmediately above. This causes atmospheric pressure to flip sheet 104upwards into place. When this happens, it immediately tends to block theslit 101 causing a high vacuum to occur in 102. This sudden increase inthe vacuum pressure closes the electrical switch 106 causing theactuator 16, through hydraulic ram 16 or other known actuating means, toraise the leveling'plate 15, whereby sheet 104 will then move upward andbe accumulated at the bottom of stack 105. As soon as sheet 104 movesupward beyond the slit 101, the vacuum pressure in 102 drops and theelectrical switch 106 causes the actuator to stop until the next sheetflips into the accumulating cycle.

In FIG. 7 is shown a modified rack or buck in which the stack is inposition where all the sheets are in alignment. Side 31 is slightlyinclined and base 30 is at right angles thereto. This has certainadvantages in subsequent handling of the sheets.

In some cases, it might be convenient to have a threesided and possiblya four-sided head. Also, in some cases,

a cavity along only one side in combination with the cavity within theplate is sufficient.

In reverse of the accumulation feature of the head assembly, the headcan travel to the depot and pick up a full stack of material and returnto its position over a conveyor. If the leveling plate is then set invertical down- Ward motion, it Will release a plate at a time as thebottom plate is forced downward by the action of the leveling plate,thus breaking the pump effect between the .top surface of the bottomsheet and the accumulated stack. In other words, the head assembly wouldspit out each plate at a rate programmed to meet the operation at theother end of the conveyor.

What is claimed is:

1. Apparatus for transporting sheets comprising a support, a headsecured to said support, said head having a recess for the reception ofa stack of sheets, a leveling plate in said head adapted to contact thetop of said top sheet, a cavity in said head connected to a source ofvacuum, the edges of said sheets communicating with said cavity, saidvacuum drawing air from between said sheets to maintain said sheets in astack supported by the head, and means for raising a sheet into saidhead.

2. Transporting apparatus according to claim 1 in which said head has atleast one depending side against which the edges of said sheets abut andin which said cavity is formed.

3. Transporting apparatus according to claim 1 in which said head hastwo adjacent angularly placed depending sides against which the edges ofsaid sheets abut and in which said cavity is formed.

4. Transporting apparatus according to claim 1 in which said support ispivoted.

5. Transporting apparatus according to claim 1 in which said support ismounted for lateral movement.

6. Transporting apparatus according to claim 2 in which the plane ofsaid side is at an angle other than a right angle to the plane of saidsheets.

7. Transporting apparatus according to claim 2 in which an actuator insaid head connected to said plate is adapted to move substantiallyvertically.

8. Transporting apparatus according to claim 2 in which a perforatedsheet covers said cavity and against which the edges of said sheetsabut.

9. Transporting apparatus according to claim 2 in which said raisingmeans is a table with means for raising said table to lift a sheet intocontact with the lowest sheet of said stack.

10. Transporting apparatus according to claim 9 in which a conveyor forsaid sheets comprises a plurality of spaced belts, said conveyor passingabove said table, said table adapted to pass upwardly through the spacebetween said belts to raise a sheet.

11. Transporting apparatus according to claim 9 in which a slit in saidsupport below said stack constitutes a narrow passage connected to saidvacuum, the free end of said slit being above a sheet to be stacked.

12. Transporting apparatus according to claim 11 in which the vacuumpressure in the duct for said vacuum is relatively low and the raisingof said sheet to be stacked is adapted to block said slit.

13. Transporting apparatus according to claim 12 in which a switchoperated by increase in vacuum pressure in said duct actuates themovement of said head.

References Cited UNITED STATES PATENTS 2,249,201 7/ 1941 Ferguson 214-12,716,497 8/1955 Wahl et al. 2141 2,920,916 1/1960 Pagdin 214-13,040,920 6/1962 Harris 214-1 3,118,554 1/1964 Brainard et a1. 2 94-65FOREIGN PATENTS 882,378 10/1959 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

I. E. OLDS, Assistant Examiner,

1. APPARATUS FOR TRANSPORTING SHEETS COMPRISING A SUPPORT, A HEADSECURED TO SAID SUPPORT, SAID HEAD HAVING A RECESS FOR THE RECEPTION OFA STACK OF SHEETS, A LEVELING PLATE IN SAID HEAD ADAPTED TO CONTACT THETOP OF SAID TOP SHEET, A CAVITY IN SAID HEAD CONNECTED TO A SOURCE OFVACUUM, THE EDGES OF SAID SHEETS COMMUNICATING WITH SAID CAVITY, SAIDVACUUM DRAWING AIR FROM BETWEEN SAID SHEETS TO MAINTAIN SAID SHEETS IN ASTACK SUPPORTED BY THE HEAD, AND MEANS FOR RAISING A SHEET INTO SAIDHEAD.